highaltitude.log.20080321

[00:01]natrium42(n=alexei@CPE000625d867e2-CM0014045885be.cpe.net.cable.rogers.com)joined #highaltitude.[00:04] <RocketBoy> night all[00:04] <edmoore> ok bed[00:04] <edmoore> cya later[00:04] <natrium42> hi[00:04] <natrium42> and bye[00:04] <natrium42> :([00:04] <edmoore> lol[00:04] <edmoore> well timed[00:04] <natrium42> yeah, eh...[00:04]RocketBoy(n=grunge@217.47.75.27)left irc: "Leaving"[00:08]edmoore(n=edmoore@88.212.167.121)left irc: [00:29]flowolf(n=flowolf@host171-56-dynamic.181-80-r.retail.telecomitalia.it)joined #highaltitude.[01:21]flowolf(n=flowolf@host171-56-dynamic.181-80-r.retail.telecomitalia.it)left irc: "Leaving"[02:32]Laurenceb(n=laurence@dhcp39-083.sthughs.ox.ac.uk)left #highaltitude ("Leaving").[02:33]MetaMorfoziS(n=avr@3e70d272.adsl.enternet.hu)left irc: Remote closed the connection[02:43]phatmonkey(n=ben@81.2.121.150)left irc: [02:51]akawaka(n=akawaka@external.treyarch.com)left irc: Read error: 110 (Connection timed out)[05:35]akawaka(n=akawaka@cpe-76-173-152-142.socal.res.rr.com)joined #highaltitude.[07:10]natrium42(n=alexei@CPE000625d867e2-CM0014045885be.cpe.net.cable.rogers.com)left irc: "pwned!"[08:32]edmoore(n=edmoore@88.212.167.121)joined #highaltitude.[08:38]Laurenceb(n=laurence@dhcp39-083.sthughs.ox.ac.uk)joined #highaltitude.[08:43]akawaka(n=akawaka@cpe-76-173-152-142.socal.res.rr.com)left irc: Read error: 110 (Connection timed out)[08:55]akawaka(n=akawaka@cpe-76-173-152-142.socal.res.rr.com)joined #highaltitude.[08:55]MetaMorfoziS(n=avr@3e70d272.adsl.enternet.hu)joined #highaltitude.[09:06]edmoore(n=edmoore@88.212.167.121)left irc: [09:32]flowolf(n=flowolf@host171-56-dynamic.181-80-r.retail.telecomitalia.it)joined #highaltitude.[09:40]Akadecca(n=akawaka@cpe-76-173-152-142.socal.res.rr.com)joined #highaltitude.[09:47]akawaka(n=akawaka@cpe-76-173-152-142.socal.res.rr.com)left irc: Read error: 110 (Connection timed out)[09:56]edmoore(n=edmoore@88.212.167.121)joined #highaltitude.[10:20]Akadecca(n=akawaka@cpe-76-173-152-142.socal.res.rr.com)left irc: Read error: 110 (Connection timed out)[10:43]phatmonkey(n=ben@81.2.121.150)joined #highaltitude.[11:22] <Laurenceb> hey all[11:23] <Laurenceb> I'm thinking of doing some more work on the zagi project, I'll try and get some boards made for the flight computer using pcbcart.com[11:24] <Laurenceb> and swap to mage324p instead of the mega64 on the previous design[11:28] <edmoore> a nice device![11:28] <Laurenceb> it is[11:28] <Laurenceb> as is http://uk.farnell.com/1299316/semiconductors/product.us0?sku=TAIWAN-SEMICONDUCTOR-TSM2302CX&_requestid=58342[11:28] <Laurenceb> for cutdowns :P[11:29] <Laurenceb> 10A pulse, 0.45 threshold voltage ![11:29] <edmoore> nice![11:29] <Laurenceb> I can make the board insanely small with those[11:29] <edmoore> we've had lotsa luck with the logic level mosfets in to220 so we're sticking with them, but actually those devices are very nice[11:30] <edmoore> am sure I could think of some apps :)[11:30] <Laurenceb> yes, t0220 is just a bit big[11:30] <Laurenceb> to*[11:31] <edmoore> if you could get some logic level ones in those packages, i'd buy 100[11:31] <Laurenceb> it is logic level[11:31] <Laurenceb> but with the thermopile unit being so small, if I can make it work with my radio board and a small gps it would work in a really ssmall flying wing[11:32] <edmoore> there's a link I must find for you......[11:32] <edmoore> gimme a sec[11:33] <edmoore> http://www.continentalctrls.com/[11:33] <edmoore> have a look at the TGE[11:33] <edmoore> it's wee[11:35] <Laurenceb> nice[11:35] <Laurenceb> but thermopiles are a bit easier[11:35] <Laurenceb> and cheaper[11:40] <Laurenceb> I'll swap to these for the voltage regulators - http://uk.farnell.com/1100656/semiconductors/product.us0?sku=MICREL-MIC5219YM5-TR[11:41] <Laurenceb> rather than the to220 ones previously[11:42] <Laurenceb> 500ma is nice :P[11:43] <Laurenceb> I'm hesitant about using a switcher, want to keep it simple[11:47] <Laurenceb> oh I was playing with some figures the other day, and its possible to run a small tesla coil directly off pwm from an avr clocked at 20mhz - you could do audio modulation really easily[11:47] <Laurenceb> the pwm would be going at a few 100Khz[11:48] <edmoore> yes, I believe the ones on t'bed normally modulate ontop of a 40khz switcher[11:49] <edmoore> t'web*[11:49] <edmoore> agree about the linears - a bit of payload capsule heating can't hurt[11:49] <edmoore> will keep the radio xtal more stable, if anything[11:50] <Laurenceb> yes, the switched mode supply seemed to be what screwed up on the rogallo[11:50] <edmoore> need to eat some ice-cream now[11:50] <edmoore> all in the name of science[11:50] <Laurenceb> :D[11:51] <edmoore> the polystyrene cases are so cool![11:51] <Laurenceb> I'm still at uni :([11:51] <Laurenceb> going home sunday[11:51] <edmoore> easter lunch?[11:51] <Laurenceb> hopefully[11:52] <Laurenceb> just been moving my stuff back to my room from the lab, I "borrowed" a few components[11:53] <Laurenceb> I now have a thermopile amp, might make a reflow oven[11:53] <edmoore> I'm about to make one[11:53] <edmoore> going to homebase soon to have a peek for something cheap[11:53] <edmoore> and moddable[11:53] <Laurenceb> cool, where are you going to get solder paste?[11:53] <edmoore> rapid, I was thinking[11:53] <edmoore> they had some last i checked[11:53] <Laurenceb> ah sweet[11:53] <edmoore> making stencils could be an interesting one[11:54] <Laurenceb> yes, I was going to leave that for the first attempts, but maybe its wise[11:54] <edmoore> it could be reason #278 to invest in a sherline mill[11:54] <edmoore> oh same[11:54] <edmoore> but in the long run[11:54] <edmoore> if there's an easy way to do it, may aswell[11:54] <Laurenceb> I'm wondering relay or rectifier and fets[11:54]MetaMorfoziS(n=avr@3e70d272.adsl.enternet.hu)left irc: Remote closed the connection[11:54] <Laurenceb> or some fancy AC stuff even...[11:54] <edmoore> for what?[11:55] <Laurenceb> turning the heater on/off[11:55] <edmoore> oh, the heat cointrol[11:55] <edmoore> sorry was still metally on stencils :)[11:56] <Laurenceb> I'm not sure what will happen if you use a rectifier with that sort of power... might muck up the mains a bit[11:56] <edmoore> will consult instructable, the source of everything[11:56] <edmoore> I'm happy to just do something tried-and-tested for this[11:57] <Laurenceb> hmm might be a plan[11:57] <edmoore> can make a nice GUI later[11:57] <Laurenceb> I've never made anything with high voltage AC (aka mains)[11:58] <edmoore> me neither, though I've been zapped hy it a few times[11:58] <Laurenceb> hehe[11:58] <Laurenceb> I once split acid over myself while making guncotton[11:59] <edmoore> whoops[11:59] <Laurenceb> it wasnt too bad, but as I frantically washed it off, all the water went over some plugs[11:59] <edmoore> there's a greaqt photo of henry on his site[11:59] <Laurenceb> and I got zapped[11:59] <edmoore> lemme find it.....[12:02] <edmoore> http://henryhallam.cjb.net/images/NaClO3.jpg[12:02] <Laurenceb> ah cool henry has a site :P[12:02] <Laurenceb> o no :([12:03] <Laurenceb> thanx bad :( poor henry[12:06]jatkins(n=jatkins@79-65-121-163.dynamic.dsl.as9105.com)joined #highaltitude.[12:10] <Laurenceb> Rogallo :D http://henryhallam.cjb.net/images/hg/meflying1.JPG[12:11] <edmoore> lol[12:11] <Laurenceb> looks fun[12:13]borism(n=boris@84-50-229-9-dsl.krw.estpak.ee)left irc: Read error: 145 (Connection timed out)[12:15] <edmoore> http://www.circuitcellar.com/library/print/0704/Lacoste_168/index.htm[12:18] <Laurenceb> he I have an AD595 from the lab[12:19] <edmoore> I might use an arduino for this[12:19] <edmoore> s'not complicated, saves faff[12:19] <Laurenceb> just use a mega168 on breadboard[12:19] <edmoore> I have an arduino![12:19] <Laurenceb> lol[12:20]Action:Laurencebwants an xmega avr[12:20] <Laurenceb> they are only shipping to +10K buyers :([12:21] <edmoore> give it time[12:21] <edmoore> they'd be great for a modem[12:22] <Laurenceb> onboard DAC[12:22] <edmoore> exactly[12:22] <edmoore> and the usual dma bells and whistle[12:22] <edmoore> s[12:22] <Laurenceb> I've been trying to get my head around DMA[12:23] <edmoore> well it makes sense conceptually, though can often be another cause of head-scartching come programming time[12:23] <edmoore> but for still like, say, copying a large buffer from ram to an sd card, it's brilliant[12:24] <edmoore> just the kind of thing you don't want the CPU to be wasting time on[12:24] <Laurenceb> so you load in a pointer to your data, the size of the data, the adress of the hardware, and some control stuff from the hardware, and it fires off an interrupt on completion?[12:24] <Laurenceb> ( I'm basing that on some avr32 code)[12:24] <edmoore> well it needn't even fire off an interupt[12:24] <Laurenceb> sure, but that helps[12:24] <edmoore> you can just get, say, the dma to read adc1 and stick it in some address automatically on a timer and you never have to bother with it again[12:25] <edmoore> you just read the address space and the latest reading is there[12:25] <Laurenceb> yes[12:25] <edmoore> mujic![12:25] <Laurenceb> how do you setup the timer?[12:25] <edmoore> but the whys and wherefors seem to vary from chip to chip[12:25] <edmoore> you'd have to have a look at the datasheet[12:25] <edmoore> for the specific device[12:25] <Laurenceb> it would have to be some sort of logic outside of the main system[12:26] <Laurenceb> if you see what I mean...[12:26] <edmoore> yes[12:26] <Laurenceb> so you have configuration registers?[12:26] <edmoore> so you'd initilise everything[12:26] <Laurenceb> yes[12:26] <edmoore> and there'd be registers[12:26] <edmoore> yeah[12:26] <Laurenceb> ok, pretty standard[12:26] <edmoore> and then it should just stay as it is once you've set it all up[12:26] <Laurenceb> so you'd be e.g "redirecting" the timer overflow flag to the dma[12:27] <edmoore> yes[12:28] <Laurenceb> too much stuff to make :S too many possibilities....[12:28] <edmoore> I know![12:28] <edmoore> I'm just drooling over what I could do with a blackfin now[12:29] <edmoore> Could make everything on a credit-card size pcb[12:29] <edmoore> full EKF state estimation, flight control, housekeeping and logging with all the bells and whistles, modem, and an OS[12:29] <edmoore> without breaking a sweat[12:31] <Laurenceb> sure[12:31] <edmoore> just need a year sabatical to make the damn thing![12:31] <edmoore> We've plenty of room left in our ARM anyway[12:31] <Laurenceb> but .... I think I can run a zagi off a single mega324p[12:31] <edmoore> so all these fantasies will have to be put asside for now :)[12:32] <edmoore> the flight control is *never* the space consuming bit[12:32] <Laurenceb> in fact I think you could run a zagi off a mega168, but I cant be bothered to optimise the code that much[12:32] <edmoore> it's the BS like fat32, USBbulk and that stuff that takes up space[12:32] <Laurenceb> yes[12:32] <edmoore> anyway, luch[12:32] <edmoore> cya later![12:32] <Laurenceb> at the moment my code is 22K (its up on the wiki)[12:32] <Laurenceb> cya[12:32]edmoore(n=edmoore@88.212.167.121)left irc: [12:41]jatkins(n=jatkins@79-65-121-163.dynamic.dsl.as9105.com)left irc: " HydraIRC -> http://www.hydrairc.com <-"[13:11]edmoore(n=edmoore@88.212.167.121)joined #highaltitude.[13:34]edmoore(n=edmoore@88.212.167.121)left irc: [13:40]Simon-MPFH(n=simon@phantom.mpfh.co.uk)joined #highaltitude.[13:57]flowolf(n=flowolf@host171-56-dynamic.181-80-r.retail.telecomitalia.it)left irc: Read error: 148 (No route to host)[14:05]borism(n=boris@84-50-229-9-dsl.krw.estpak.ee)joined #highaltitude.[14:10]borism(n=boris@84-50-229-9-dsl.krw.estpak.ee)left irc: Client Quit[15:01]borism(n=boris@84-50-229-9-dsl.krw.estpak.ee)joined #highaltitude.[15:47]edmoore(n=edmoore@88.212.167.121)joined #highaltitude.[16:23] <Laurenceb> hey edmoore[16:23]Akadecca(n=akawaka@cpe-76-173-152-142.socal.res.rr.com)joined #highaltitude.[16:48]Akadecca(n=akawaka@cpe-76-173-152-142.socal.res.rr.com)left irc: Read error: 110 (Connection timed out)[17:17]neontube(n=davemart@neontube.plus.com)joined #highaltitude.[17:17] <neontube> afternoon all[17:17] <neontube> long time no see[17:17] <edmoore> 'ello[17:17] <edmoore> how's life?[17:17] <neontube> Ebay: 230234375388 - weather sat receiver if anyone is interested[17:18] <neontube> not bad[17:18] <neontube> extreamly busy at work though[17:18] <neontube> in the middle of changing 430 schools from one internet provider to another[17:18] <neontube> which includes 40,000 email accounts[17:18] <neontube> & 300 + websites[17:19] <edmoore> lol[17:19] <edmoore> sounds like a fun afternoon[17:20] <neontube> 3 weeks and email still isn't right[17:20] <neontube> moved from a unix / IBM system to a windows exchange system,[17:20] <neontube> we have to move over user accounts/passwords, and all emails in there account (its a web based system)[17:22]MetaMorfoziS(n=avr@3e70d272.adsl.enternet.hu)joined #highaltitude.[17:26] <edmoore> I want to build me a wee server now[17:29] <neontube> as in Wii ?[17:29] <neontube> or just small server :P[17:31] <edmoore> small :)[17:46]Hiena(n=Hiena@81.93.195.181.datatrans.hu)joined #highaltitude.[17:46] <Hiena> Good evening![17:57] <edmoore> hi![17:57] <edmoore> just been hit by an awesome storm[17:58] <neontube> as for small servers... i have a mac mini in the loft[17:58] <edmoore> That would be ideal[17:59] <edmoore> but equally for the money, you can do a lot if you DIY[17:59] <neontube> indeed[17:59] <neontube> 180 quid for an old mac mini though[17:59] <edmoore> not bad[17:59] <neontube> they are virtualy scilent[17:59] <edmoore> tho I want RAID as it;s going to host all the important balloon and courseowrk and life SVN stuff[18:00] <neontube> humm...[18:00] <neontube> i personaly go for a manual backup to external HDD[18:01] <edmoore> good idea, though increasingly I want to ditch all the laptop clobber and have an eeepc with everything accessible from the web[18:01] <edmoore> but that's a bit off[18:01] <neontube> fair do[18:02] <edmoore> My current 15.4" laptop is a pain to lug around uni all day every day[18:03] <neontube> indeed, you should see my laptop bag ![18:03] <neontube> laptop - network tester - full set of tools - reference manauals + all my uni stuff ![18:04] <Hiena> Ehem...[18:04] <Hiena> Welcome to the 21th century.[18:08] <Hiena> Hmmm... Bad weather fro the three day weekend: Checked, 3 BFR94 bough for nothing: Checked, A car with a fresh technical licence: Checked, RF modulator+CCD camera+GPS: Checked, Half finished ring-wing: Checked, Estimation: Somebody not will sleep this weekend...[18:14]akawaka(n=akawaka@external.treyarch.com)joined #highaltitude.[18:14] <akawaka> morning[18:14] <edmoore> morning[18:15] <Hiena> Already?[18:23] <edmoore> not me[18:23] <edmoore> 18:23 round these parts[18:24] <Hiena> Yup.[18:30] <edmoore> woooooooooooo[18:30] <edmoore> I got me a summer job[18:45]mc-(n=mfcastle@cpc4-glfd1-0-0-cust538.glfd.cable.ntl.com)joined #highaltitude.[18:45] <akawaka> congrats[18:49] <mc-> ed, what's your job?[18:56] <edmoore> working for Vorticity systems doing the descent systems for extra-terreestrial landers[18:57] <edmoore> They did the Huygens descent system, among other things, and are doing ExoMars atm[18:57] <edmoore> space toys!!![19:14]edmoore(n=edmoore@88.212.167.121)left irc: [19:40]edmoore(n=edmoore@88.212.167.121)joined #highaltitude.[19:50]natrium42(n=alexei@CPE000625d867e2-CM0014045885be.cpe.net.cable.rogers.com)joined #highaltitude.[19:54]edmoore(n=edmoore@88.212.167.121)left irc: [20:16]edmoore(n=edmoore@88.212.167.121)joined #highaltitude.[20:37]duke3k(i=duke3k@24-182-229-4.dhcp.stls.mo.charter.com)joined #highaltitude.[20:37]duke3k(i=duke3k@24-182-229-4.dhcp.stls.mo.charter.com)left #highaltitude.[20:42]neontube(n=davemart@neontube.plus.com)left #highaltitude.[20:49] <mc-> nice job![20:57] <Hiena> mc-, last time you asked, who made the trashbag balloon, what i linked to you. That contraption builder was me.[21:22] <mc-> very nice.[21:28] <Hiena> No not nice. The 30 bag in one will be nice. ;)[21:30]Simon-MPFH(n=simon@phantom.mpfh.co.uk)left irc: "Leaving"[21:31]Hiena(n=Hiena@81.93.195.181.datatrans.hu)left irc: "-=Alkoholmentes-sör és repülõgép-szimulátor, biztos út a guminõ felé=-"[21:35]RocketBoy(n=grunge@217.47.75.27)joined #highaltitude.[21:37] <edmoore> Hi Rocketboy[21:37] <edmoore> am just getting through some ice-cream[21:37] <edmoore> I can confirm that the PCBs still fit in gu boxes.[21:38] <edmoore> A useful confirmation, I'm sure you'll agree.[21:38] <RocketBoy> mummmmm - yes[21:38] <RocketBoy> what is the internal dimensions[21:38] <RocketBoy> ?[21:39] <edmoore> just shy of 90mm square[21:39] <edmoore> and about 80 deep[21:39] <edmoore> but will get some useful number later[21:39] <edmoore> there's a roughly 5mm radius on the internal corners[21:39] <RocketBoy> ok - sounds fine for the camera etc.[21:40] <RocketBoy> how thick are the walls?[21:40] <edmoore> 10mm ish[21:40] <edmoore> Will go to the garage and attack it with verniers in a bit[21:41] <RocketBoy> OK - np I just wanted to get an idea[21:41] <edmoore> will need holes in the bottom for radio and gsm antenna[21:41] <RocketBoy> It would be good to know the weight too[21:41] <edmoore> do you think the gsm would be ok pointing down/sideways out the bottom?[21:41] <edmoore> yes, I was looking for my scales[21:42] <edmoore> to weight up as much of it as I currently have - gps, telit, pcb and box[21:42] <edmoore> but they seem to have gone awol[21:42] <edmoore> is there any advnatge to making antennas larger multiples of wavelengths?[21:44] <RocketBoy> not as such - you can make co-linears (which are like dipoles stacked end on end) - these produce a more focused "beam" of RF[21:45] <edmoore> ok cool[21:45] <RocketBoy> but there is not much advantage for us - the ideal is no RF upwards - and sort of a sqished radiation pattern[21:45] <edmoore> yeah[21:45] <edmoore> though project #137 for a rainy day could be a pointing directional one back to a base-station[21:46] <mc-> RocketBoy, there's a 5/8's whip or something that doesn't need a gnd plane, isn't there?[21:46] <RocketBoy> but either the ground plane or the co-ax dipole are just about idea[21:46] <RocketBoy> ideal[21:46] <RocketBoy> yep[21:46] <mc-> was trying to make an ant for 30m band[21:47] <mc-> any suggestions?[21:47] <RocketBoy> a loaded 5/8 whip is good - not sure on the radiation pattern though - I'll look it up[21:47] <RocketBoy> 30m base station?[21:47] <RocketBoy> (not balllon)[21:47] <mc-> base station and for a balloon[21:48] <mc-> don't have either[21:48] <RocketBoy> well balllon is easy - about 5m of wire up and down from the payload[21:48] <mc-> but have all the parts on order[21:48] <RocketBoy> ooops - make that 2.5m[21:48] <mc-> doesn't a dipole need a balun as well?[21:49] <RocketBoy> ooo000oooops - 7.5m[21:50] <mc-> 30/4 ?[21:50] <RocketBoy> yeah ideally - but its not that much of an issue where there is no feeder - and there is a good match[21:50] <RocketBoy> yeah 30/4 = 7.5[21:51] <mc-> I don't know anything about baluns, so that's good I don't have to build one.[21:52] <RocketBoy> acually this less than that - it depends on the actual frequency and the wire thickness - ormally 95% of 300/(4 * freq) in MHz will get it (I think)[21:52] <edmoore> Ama gunna get me wunna dey'm ha alditood baluns[21:53] <mc-> can I do the same trick on the ground, and put the receiver by the antenna?[21:54] <RocketBoy> well - the simplest is just 7.5m of wire plugged in to the antenna socket[21:54] <RocketBoy> It depends how complex and £££ you want to make it[21:55] <RocketBoy> A 3 ele beam on a 200ft tower would be good[21:55] <mc-> I wish..[21:56] <RocketBoy> or http://www.m0rhi.co.uk/gallery/ssbfd05/100_0082[21:56] <mc-> I guess if the ant can be raised up, it has better low angle radiation.[21:57] <edmoore> It would be great to pitch one of those in churchill, and really set up a base camp for the duration of a mission[21:58] <RocketBoy> Yeah - its all possible[22:00] <RocketBoy> I'm amazed how well we do on the small yagi on a tripod - normally we can copy down to about 1000m[22:01] <edmoore> at which point GSM kicks in[22:01] <RocketBoy> yeah[22:01] <edmoore> so says theory[22:02] <mc-> found an 8m roach pole[22:03] <RocketBoy> yeah good for a ground plane[22:03] <RocketBoy> (on 10m)[22:04] <RocketBoy> BBL[22:06] <mc-> ed, did you get a soldering oven?[22:06]fuzzylugnut(n=hush@24-116-155-170.cpe.cableone.net)joined #highaltitude.[22:07] <mc-> I've got a hot air rework station, if you just soldering 1 IC.[22:09] <fuzzylugnut> mc-: do you have all the different tips for the different chips?[22:09] <akawaka> fuzzylugnut: micro-trak arrived yesterday[22:09] <edmoore> mc, no, just thinking aboot it[22:09] <mc-> no, that's expensive stuff. I just have a few basic tips.[22:10] <edmoore> but I have a hot-air too so i should just use that really[22:10] <fuzzylugnut> akawaka: yay! how do you like it?[22:10] <mc-> is it a BGA chip?[22:10] <akawaka> pretty cool[22:10] <fuzzylugnut> mc-: yeah, I'm in the same boat... each tip is like $25 a piece[22:10] <edmoore> I may be doing BGA stuff yeah[22:10] <edmoore> and plenty of QFN[22:10] <akawaka> doesn't like being powered from a plain old 9v battery though:)[22:11] <edmoore> and MLF[22:11] <mc-> or if it's Weller it $250 each[22:11] <fuzzylugnut> akawaka: oh? did you ge the 300 or 8000?[22:11] <akawaka> 8000[22:11] <akawaka> FA[22:11] <mc-> QFN are no problem[22:11] <mc-> just watch it melt the solder, then stop[22:11] <edmoore> normal solder or paste?[22:12] <mc-> paste[22:12] <fuzzylugnut> it's all over on ebay[22:12] <mc-> but you can see the edges of a QFN[22:12] <mc-> somewhere I saw you can buy stencils of the common chips[22:13] <edmoore> oooh[22:13] <fuzzylugnut> cool[22:13] <fuzzylugnut> that'd be super handy[22:13] <mc-> I think there was a link to a cheap stencil mfr on sparkfun[22:14] <fuzzylugnut> you can etch them yourself too, the steel sheets are on ebay I think.[22:15] <mc-> www.pololu.com from http://www.sparkfun.com/commerce/present.php?p=Stenciling[22:17] <edmoore> paste seems quite expensive[22:17] <fuzzylugnut> Cool[22:17] <fuzzylugnut> doing it by hand sucks on big baords : ([22:19] <mc-> you don't much paste, I've got a syringe of it in the fridge.[22:19] <mc-> But it's probably out of date now.[22:19] <fuzzylugnut> *nods*[22:20] <fuzzylugnut> I keep mine in the fridge now. I had it out for a few months and it got reallly thick.[22:21] <edmoore> I will give it a whirl[22:22] <edmoore> need to make a biiiiiiiiig farnell order[22:24] <mc-> why not rapid?[22:25] <edmoore> they don't have some of the more obscure bits[22:27] <mc-> is this your IMU?[22:28] <edmoore> various[22:28] <edmoore> partly that, some stuff for the flight computer, some specific fets for motor control, and some odds and sods[22:29] <mc-> motor control for a gimbal?[22:29] <edmoore> nope, some linacs[22:30] <edmoore> tho could be used for a gimball[22:30] <edmoore> it's basically a servo card[22:30] <mc-> what's a linac?[22:30] <edmoore> linear actuator[22:30] <fuzzylugnut> linear accelerator in my world ; )[22:31] <edmoore> yes, i was being a bit silly :p[22:31] <edmoore> it[22:31] <edmoore> whoops[22:31] <mc-> I think I've worked out what that is for...[22:32] <edmoore> yep![22:33] <mc-> you could point a telescope as well[22:34] <edmoore> oh it's not for that....[22:34] <edmoore> though actually I could make the hardware identical[22:34] <mc-> I know, but I was thinking of other uses[22:34] <edmoore> no I couldn't[22:35] <edmoore> I'll force it into being useable for both[22:35] <mc-> is the actuator something off-the-shelf?[22:36] <edmoore> if I can find a suitable one, that'd be nice, yeah[22:36] <mc-> or motor + leadscrew?[22:38] <edmoore> OTS if poss[22:39] <mc-> RC electric motor + gearbox would be lightweight?[22:39] <mc-> or why not a servo?[22:39] <edmoore> I'll need a bit more meat[22:39] <fuzzylugnut> mmmm... meat.[22:39] <edmoore> and don't want to spend on one of the really high performance digital coreless ones[22:39] <edmoore> plus linear motion is nice[22:40] <mc-> there's an open source servo group[22:40] <edmoore> yeah, that's only an i2c digital backpack to normal servos[22:40] <mc-> how fast do you need to move? or is that a leading qn?[22:41] <edmoore> faster the better. Decent response and holding torque are what I'm after[22:42] <fuzzylugnut> how about a linear motor?[22:43] <mc-> they are heavy aren't they?[22:43] <fuzzylugnut> yeah, they are[22:43] <edmoore> yeah, just a linAc will do[22:43] <mc-> is the 'instrument' balanced about its CoG?[22:44] <edmoore> by definition!?[22:44] <edmoore> oh sorry[22:44] <edmoore> misheard you[22:44] <edmoore> misread*[22:44] <edmoore> I'm not sure we're talking about the same thing[22:45] <mc-> if it's balanced, then holding torque is low?[22:45] <edmoore> see above[22:46] <mc-> I'm on 99[22:46] <edmoore> I'm not :p[22:46] <edmoore> it's just a random project[22:46] <edmoore> the antenna will be steppers[22:46] <edmoore> and far morte conventional[22:46] <edmoore> more*[22:47]RocketBoy(n=grunge@217.47.75.27)left irc: Read error: 110 (Connection timed out)[22:50] <mc-> btw, are you coming to the space conf next weekend?[22:50] <edmoore> yeah quite possibly. It'll depend on another thing but I'll come if I'm around[22:50] <edmoore> also if George Whitesides is there that'll be another reason[22:50] <mc-> did you email them, as I think they only have a few spaces left?[22:51] <edmoore> nope - I just got an email saying plenty of spaces[22:51] <edmoore> will email them[22:52] <mc-> I've arranged to meet someone from the Xprize organisers[22:53] <edmoore> oooh, whozat?[22:53] <mc-> 99[22:58] <Laurenceb> edmoore: nice job :P[22:59] <edmoore> ty![23:04] <mc-> can an aerofoil be balanced to air pressure so it doesn't need much power to move it?[23:05] <edmoore> not really[23:05] <edmoore> it'll always be a function of angualr displacement[23:05] <edmoore> and the force will tend to zero for small deviations about the midpoint[23:06] <edmoore> but it's not really applicable to anything useful[23:06] <Laurenceb> theres the moment of intertia of the vehicle to consider as well[23:06] <edmoore> what are we talking about?[23:06] <fuzzylugnut> pie? : ([23:06] <mc-> if the shaft is in the middle of the foil, then there's equal pressure on each half? Or am I misunderstanding?[23:06] <Laurenceb> nvm[23:06] <Laurenceb> thats not relevant[23:07] <edmoore> you'll have to elaborate mc-[23:07] <edmoore> if it's a symetrical aerofoil generating no lift, then the pressures are equal on either side[23:07] <mc-> sorry, if the bearing is in the middle of the aerofoil, then there's ...[23:09] <mc-> I guess it is providing lift, then the CofPressure moves away from the centre of the aerofoil?[23:10] <edmoore> it depends on what direction[23:11] <edmoore> theoretically in the direction of lift the CoP can stay the same, just with reduced pressure above and increased pressure below[23:12] <mc-> does that mean that a rudder doesn't need a large torque, if it's pivoted in the centre?[23:12] <edmoore> oh I see what you mean[23:12] <edmoore> no I think it's constant[23:13] <edmoore> wherever you put it[23:13] <edmoore> the cross-sectional area to the flow will still be constant[23:13] <edmoore> so the same force will be applied on ino I'm talking rubbish[23:13] <edmoore> in theory you're right, but flow instabilities will always ruin your day on that one[23:13] <mc-> with a centre pivot, there's no restoring force, I think...[23:14] <edmoore> it's unstable, yes[23:15] <mc-> think there's a russian missile that uses multiple vanes (like a window shutter), so that there's low force required for guidance.[23:15] <mc-> *I[23:16] <mc-> but that's probably getting difficult to build...[23:16] <edmoore> the contro, fins on the front of the eurofighter have a central pivot too[23:16] <edmoore> but then it's designed to be unstable[23:17] <mc-> I think most canards have a centre pivot[23:18] <mc-> Burt Rutan's EZE did, I think[23:18] <mc-> gotta go[23:19] <edmoore> ok, talk soon[23:19] <mc-> cya[23:19]mc-(n=mfcastle@cpc4-glfd1-0-0-cust538.glfd.cable.ntl.com)left irc: [23:19] <Laurenceb> http://www.sparkfun.com/commerce/product_info.php?products_id=8621[23:19] <Laurenceb> ^ nice[23:20] <fuzzylugnut> holy crap[23:20] <fuzzylugnut> hot.[23:21] <fuzzylugnut> price isn't bad either[23:22] <edmoore> if the person who just left can ahem-hmm-throat-clearing-noises with them, then they'd be sh!t hot[23:23] <Laurenceb> I'm just designing my new zagi board[23:23] <Laurenceb> looking for a gps to use[23:25] <edmoore> could probs do a lot worse than that[23:25] <natrium42> Laurenceb, hopefully it works at high altitude, which many sirfIII don't apparently[23:26] <edmoore> it won't[23:26] <edmoore> I can tell you that for free[23:26] <edmoore> hence3 my comment at 23:19[23:26] <fuzzylugnut> awww[23:26] <fuzzylugnut> bummer[23:27] <fuzzylugnut> its so tiny and cute. : ([23:27] <Laurenceb> anyone know where the sparkfun eagle library can be found?[23:27] <edmoore> open circuits[23:27] <edmoore> .com[23:28] <Laurenceb> got it :P[23:28] <Laurenceb> hmm where do librarys go on ubuntu?[23:29] <natrium42> edmoore, grr, i still haven't reflashed that tiny gps module i got[23:29] <natrium42> too many distractions[23:29] <edmoore> tell me about it[23:29] <natrium42> hehe[23:34] <natrium42> in other news, i have almost decided to get an iridium phone[23:34] <natrium42> just going to wait for a good deal[23:34] <edmoore> standing on ebay with a quivering finger?[23:34] <natrium42> yeah :([23:34] <natrium42> i am impulsive[23:34] <edmoore> it's a happy feeling :)[23:35] <natrium42> haha[23:40] <natrium42> edmoore, i just think buying cheap products is a waste of money, hence not globalstar[23:40] <edmoore> yeah fair enough[23:41] <edmoore> sensible in the long run[23:49] <edmoore> Laurenceb: have you a link to the linux SBC of yours?[23:50]Nick change:fuzzylugnut -> fuzzy_food[23:50] <Laurenceb> http://www.azzurri.com/store/products/atmel_ngw100.htm[23:52] <edmoore> so cheap![23:52] <edmoore> what's the current consumption and dimensions?[23:52] <Laurenceb> it doesnt need 12V[23:52] <Laurenceb> 10cm*12, about 150ma @ 8V[23:52] <Laurenceb> thats with the ethernet running and stuff[23:52] <edmoore> nice[23:52] <Laurenceb> my entire payload uses 200ma[23:53] <Laurenceb> I've bypassed one of the diodes[23:54] <Laurenceb> according to the datasheet for the switcher on the board, it will run off 6 or 7v[00:00]--- Sat Mar 22 2008